Internal combustion engines of the swash or wobble plate type



Oct. 25, 1960 c. w. CLARK 7,

' INTERNAL COMBUSTION ENGINES OF THE SWASH OR WOBBLE PLATE TYPE.

Filed Dec. 12, 1958 2 Sheets-Sheet 1 SPEED RESPONS/VE HYDRAULIC PUMPFIG.

lNvaN'roR Cum-mes W. CLARK MmM Mm ATTORNEY c. w. CLARK 2,957,462

INTERNAL COMBUSTION ENGINES OF THE SWASH OR WOBBLE PLATE TYPE Oct. 25,1960 2 Sheets-Sheet 2 Filed Dec. 12, 1958 INVENTOR CHARLES \N. CLARKUnited States Patent INTERNAL COMBUSTION ENGINES OF THE SWASH 0R WOBBLEPLATE TYPE Charles William Clark, 25 Manchester Square, London W1,England Filed Dec. 12, 1958, Ser. No. 779,908

Claims priority, application Great Britain Dec. 17, 1957 2 Claims. (Cl.123-58) This invention relates to reciprocating internal combustionengines of the kind comprising two swashplates or wobble plates arrangedto rotate at the same speed about a common axis and axially displacedfrom one another, at least two cylinders arranged with their axesparallel to and equally displaced from the rotational axis of theswash-plates or wobble plates, and two pistons arranged to reciprocatein each cylinder and to act respectively on the swash plates or wobbleplates to cause rotation thereof, the swashplates or wobble plates beingso arranged that the two pistons in each cylinder move towards and awayfrom one another while each cylinder is provided with inlet and exhaustports which are uncovered respectively by the-two pistons at the ends oftheir outward travel to permit the exit of the products of combustionand the entry of a fresh charge ready for compression into thecombustion chamber between the pistons on their next instrokes so thatthe engine operates upon the two stroke cycle.

The term swashplate or wobble plate used herein is to be understood asincluding a member having a continuous thrust surface lying in a planeinclined to its axis of rotation and acted upon through slippers or thelike by the pistons as well as a member which carries or forms one partof a thrust bearing the axis of which is inclined to the axis ofrotation of the member and which connects it to the member and is itselfconnected to the pistons. For convenience herein the term swashplatewill be used to include both such known arrangements. Nevertheless theinvention is particularly though not exclusively applicable to enginesof the type in question in accordance with the present applicantsBritish Patent No. 762,777.

A reciprocating internal combustion engine of the kind referred toaccording to the present invention includes means by which the openingperiods of the inlet and/or exhaust parts by the pistons can be variedto suit different running conditions. Such means may be arranged toalter the phase relationship between the two swashplates so as to alterthe relationship between the periods of opening respectively of theinlet and exhaust ports in each cylinder and/or to vary the axial lengthof the inlet ports and/or the exhaust ports to vary the moment ofopening and/or closing of the inlet and/or exhaust ports in relation toone another and/or the rotational position of the swashplates.

Thus in one form of the invention one or each of the swashplates may bemovable relatively to the cylinders in a direction parallel to the axisof the cylinders, in which case the swashpl-ates may be mounted on acommon main shaft extending between them and on which one or each ofthem can slide axially. Moreover in such a case the connection betweenone of the swashplates and the main shaft may be such that as it ismoved axially it also rotates relatively to the main shaft as by beingconnected to the main shaft through helical splines.

Alternatively the swashplates may be mounted upon separate coaxial mainshafts which are connected to one 2,957,462 Patented Oct. 25, 1960another through a coupling member capable of sliding axially relativelythereto, one of the connections being such that the axial movementproduces no relative rotation between the shaft and the coupling whilethe other is such that such relative rotation is produced as by theconnection being through helical splines. It will be apparent that ineach of the above arrangements embodying a helical spline or likeconnection the adjustment will produce a change in the phaserelationship between the swashplate and hence between the movements ofthe pistons connected respectively to them.

Alternatively or in addition one or each of the pistons in each cylindermay be arranged to operate with in a sleeve which is axially adjustablein the cylinder to vary the period of opening of the ports controlled bythat piston.

In all arrangements according to the invention the means by whichadjustment is effected are capable of being operated during operation ofthe engine so that adjustment can be effected during such operation tosuit operating conditions. It is thus possible with the invention tovary the timing of the inlet and exhaust port opening periods in eachcylinder to suit operating conditions, and the means would convenientlybe arranged to be adjusted automatically in accordance with the speed ofthe engine.

The two examples of the invention are shown diagrammatically in theaccompanying drawings, in which Figure 1 is a somewhat diagrammatic sideelevation, mainly in section, of one arrangement.

Figure 2 is an end elevation showing one of the wobble plates amembliesof Figure 1 and indicated generally at 1, in which are formed or rigidlycarried two cylinders indicated generally at 2 and 3, the axes of thecylinders being spaced from one another and parallel to one another andlying on diagrammatically opposite sides of a main shaft 4 which issupported in bearings 4a in the body 1. Each of the cylinders 2 and 3has formed in its wall inlet and exhaust ports 5 and 6 communicatingrespectively with an inlet passage 7 and an exhaust passage 8. The inletpassages 7 are connected to an air compressor 7a and the effectivepositions of the edges of the inlet and exhaust ports 5 and 6 aredetermined respectively by the axial positions of two sleeves 9 and 10mounted to slide within the outer ends of the cylinders and forming ineffect the outer ends of the cylinder bore.

A fuel injection device 11 is mounted in each cylinder wall adjacent tothe centre of its length, that is to say in the part of the cylinderwhich constitutes the combustion chamber. The axial positions of the twosleeves 9 and 10 are controlled by levers indicated at 12 and 13 for thecylinder 2 and omitted for convenience of illustration as regards thecylinder 3. Thus as regards the sleeves 12 and 13 associated with thecylinder 3 the levers 12 and 13 and associated control mechanismhereinafter described, and shown associated with cylinder 2 would bedisposed behind cylinder 3 in Figure l.

Arranged to reciprocate within each cylinder are pistons 14 and 15 whichact through connecting rods 16 on swashplates 17 and 18 through bearingsindicated at 19. Each of the swashplates 17 and 18 is connected to thecasing 1 by a pair of coaxial trunnions 17a or 18a and is connected byinclined bearings 20 to a supporting member 21 or 21a carried by andarranged to rotate with the main shaft 4. The arrangement is thussimilar to that described and shown in British patent specification No.762,777.

The supporting member 21 is connected to the main shaft 4 by parallelsplines as indicated at 22, while the member 21a is connected to themain shaft 4 through helical splines indicated at 23, and leversindicated at 24 and 25 controlled by cams indicated at 26 are providedby which the members 20 and 21 can be moved axially relatively to thecylinders 2 and 3.

It will therefore be seen that by moving the member 21 axiallyrelatively to the cylinders by operation of the appropriate cam 26 boththe timing of the opening of the ports 6 and if desired the compressionratio of the engine can be varied, while by similarly moving the member21a axially the timing of the opening of the ports and the phaserelationship between the movements of the pistons 14 and 15 can bevaried. Further byadjustment of the sleeves 9 and 10 by the levers 12and 13 the opening periods respectively of the inlet and exhaust portscan be varied.

The cams 26 and the levers 12 and 13 may moreover be connected tospeed-responsive control mechanism by which they are moved automaticallyin accordance with changes in the speed of rotation of the shaft 4. Suchmechanism may be of known hydraulic type and in the example showncomprises a speed-responsive hydraulic device 28 including in knownmanner a hydraulic pump driven from the shaft 4 through drivingmechanism indicated at 29 and constructed so as to produce and maintainin pipe lines 30 a pressure dependent upon the speed of the shaft 4 andpiston type hydraulic servo devices 31 and 32 subject to the pressure inthe pipe lines 30 and having their pistons connected by connecting rodsystems indicated generally at 33, 34, 35 and 36 respectively to thelevers 12 and 13 and the earns 26 acting on the levers 25 and 24.

Thus during operation of the engine the positions of the cams 26 and ofthe sleeves 9 and 10 are varied automatically by and are dependent uponthe engine speed.

The movement imparted to the earns 26 and the levers 12 and 13 withvariations in engine speeds will be such as to suit the characteristicsof the particular engine concerned and would be determined in accordancewith those characteristics in the manner hereinafter described.

In the alternative arrangement shown diagrammatically in Figure 3 thegeneral construction and disposition of the cylinders, indicated at 37,will be the same as the cylinders 2 and 3 in the construction shown inFigure 1 the cylinders, however, being in this case of normal openendedform without embodying sleeves similar to the sleeves 9 and 10 inFigure 1. It will be understood that the cylinders will be provided inknown manner with inlet and exhaust ports arranged to be uncovered bypistons indicated at 38 and 39 therein. Moreover the pistons areconnected to swashplates 17 and 18 similar to the swashplates 17 and 18shown in Figure 1, these swashplates being connected through appropriatebearings similar to the bearings 22 to supporting member 40. In thisconstruction, however, instead of a one-piece main shaft 4 as shown inFigure 1 the main shaft comprises two sections 41, 42 each individuallymounted in bearings in part of the body of the engine indicated at 43.The two shaft parts 42, 43 are connected respectively to the twosupporting members 49 through parallel splines as indicated at 44 andare connected to one another by a sleeve '45 which is arranged to rotatewith them and is connected to the shaft part 41 by parallel splines 46and to the shaft part 42 by helical splines 47. The sleeve 45 isarranged to be axially movable relatively to the two shaft parts bymeans of an operating fork indicated at 48 and it will be apparent thatthis movement will cause rotation of the shaft part 41 relatively to theshaft part 42 and thus vary the phase relationship between thesupporting members 40 and hence between the movements of the two pistonsin each cylinder.

In this arrangement the operating fork 48 could be connected tospeed-responsive actuating apparatus, for

example hydraulic apparatus similar to that operating one of the levers24, 25 in Figure 1, so that the phase relationship is variedautomatically in some predetermined manner in accordance with the speedof rotation of the shaft 41, 42.

The manner in which the control means embodied in engines according tothe invention are moved in accordance with speed changes will varyaccording to the characteristics of the engine concerned and theappropriate movements would normally be determined by experimentaloperation of any particular engine having such control means over itsworking range. Thus under each operating condition within theappropriate range of operating conditions the control means would beadjusted manually to determine what adjustment gives to the maximumdegree the desirable operating characteristics for that condition. Theautomatic control means would then be arranged so that it moves theappropriate parts, as through the cams and levers to providesubstantially the best operating conditions over the whole speed range.

In this connection it is well recognised that existing internalcombustion engines, and particularly high etficiency internal combustionengines, have compression ratios and timing for inlet and exhaust portopenings which represent a compromise aimed at meeting to a reasablysatisfactory degree the required conditions, but that this results inthe ideal requirements having to be to some degree sacrificed under eachrunning condition. For example, the port timing appropriate to give themaximum efiiciency at high speed is frequently inefiicient and wastefulat lower speeds, while starting may be rendered diflicult by use of aport timing which gives maximum power output at high speed. The presentinvention thus aims at providing an engine of the particular kind towhich the invention relates in which the best operating conditions overthe whole operating range of the engine can be more nearly approachedthan in existing engines.

What I claim as my invention and desire to secure by Letters Patent is:

1. A reciprocating internal combustion engine comprising two swashplatesarranged to rotate at the same speed about a common axis and axiallydisplaced from one another, at least two cylinders arranged with theiraxes parallel to and equally displaced from the rotational axis of theswashplates, two pistons arranged to reciprocate in each cylinder and toact respectively on the swashplates to cause rotation thereof, thepistons in each cylinder moving towards and away from one another andeach cylinder being provided with inlet and exhaust ports which areuncovered respectively by the two'pistons at the ends of their outwardtravel to permit the exit of exhaust gases and the entry of a freshcharge, sleeves axially movable in the cylinders and controlling theeflective length of the ports, mechanisms controlling the positions ofthe sleeves, and speed-responsive means controlling said mechanisms.

2. A reciprocating internal combustion engine as claimed in claim 1 inwhich the mechanisms controlling the sleeves act independently on eachof the sleeves.

References Cited in the file of this patent UNITED STATES PATENTS 46,672Patton July 13, 1920 ,716,020 Winckler June 4, 1929 ,968,470 SzombathyJuly 31, 1934 ,0 7,051 Smiley Apr. 14, 1936 2, ,362 Barkeij Dec. 8, 19363,480 Kadenacy Apr. 5, 1938 1, 86 Deschamps Dec. 2, 1947 OTHERREFERENCES German application K 16993, 121/ 59a. Published Mar. 22,1956,

